1. Field of the Invention
The present invention relates to gaskets. More particularly, the present invention relates to a gasket that enables gas to be vented from a package, while preventing a liquid from leaking therefrom. The gasket is particularly suited for use in a spray or pump package.
2. Description of the Prior Art
Many liquid products are placed and held in a package that may take the form of a bottle or container. Often the package has a dispensing mechanism, such as a trigger spray or finger pump integrated into the package.
These systems may hold liquids that volatilize into a gas, which increases the pressure inside the package creating a positive pressure gas generating system. In a closed bottle or container, the positive pressure gas generating system can build up pressure that will ultimately distort the package. In fact, if the pressure is great enough, the package could burst and release the liquid held inside. To resolve this problem, gaskets have been made that permit excess gas to exit the package while preventing the liquid contained within from leaking out. These gaskets have a single gas permeable layer bonded to a core that prevents liquid from leaking out. DURAVENT gaskets manufactured and sold by W. L. Gore and Associates, exemplify such gaskets. They are designed so that one side of the gasket allows gas to enter or escape a container along the threads of a cap.
However, in order for the gasket to function properly, the gasket must be positioned in the assembled piece so that the gas permeable layer is facing the liquid side. To properly place the gasket in the workpiece requires the use of an orientation device, i.e., human or mechanical means. This extra manufacturing step can significantly increase the manufacturing costs of the finished product.
It is an object of the present invention to provide a gasket that is capable of venting gas from a package, such as a bottle or a container.
It is another object of the present invention to provide such a gasket that prevents liquid from leaking out of the package.
It is still another object of the present invention to provide such a gasket that is used in connection with a spray or pump dispenser.
It is still yet another object of the present invention to provide such a gasket that can be positioned in a closure fitting without using an orientation device.
It is a further object of the present invention to provide a method for venting gas from the package, while preventing liquid from leaking therefrom.
To accomplish the foregoing objects and advantages, the present invention, in brief summary, is a multi-layer gasket that is capable of venting gas from a bottle or a container while preventing liquid from leaking. The gasket is particularly suited for use in connection with a spray dispenser, such as a trigger spray, or pump dispenser, such as a finger pump. The gasket comprises a liquid impermeable core having a first side and a second side, and a first gas permeable outer layer connected to the first side and a second gas permeable outer layer connected to the second side opposite the first layer. More preferably, the core and two outer layers are laminated together.
The present invention also includes a method for relieving and preventing gas pressure buildup in a package, by utilizing a closure fitting having the gasket of the present invention that allows for passive venting of excess gas pressure from the package. The method comprises the step of securing a closure fitting having a gasket of the present invention about an opening of a package without the need for orientation of the gasket.